Often, reconstructive procedures used in medicine and dentistry in particular involve the manipulation and healing of bones. Such procedures may involve changes in the position, orientation, shape and size of skeletal structures. A problem that is commonly encountered during such procedures is a lack of a bone graft, e.g., bone from another part of the patient. Bone graft material may be used in several applications, such as to fill between sections of bone that have been repositioned, to change surface geometry, or to add bone to an area that is deficient, such as in conjunction with periodontal surgery or dental implants in the patients' jaws.
Indeed, today, intraoral bone grafting procedures have become an almost integral part of dental implant reconstruction. In many instances, a potential implant site in the upper or lower jaw does not offer enough bone volume or quantity to accommodate a rootform implant of proper size or in the proper place. This may be the result of bone resorption that has taken place since one or more teeth (if not all) were lost. Bone grafting procedures in this case usually try to re-establish bone dimension which was lost due to resorption.
Although there are several materials, both natural and artificial, that can be used for bone grafting, the best material is bone from a donor site of the patient which is removed therefrom and placed somewhere else in the body, i.e., into a recipient site. This is often referred to as an autogenous graft or autograft. The best success rates in bone grafting have typically been achieved when the patient's own bone material is used because the bone is living tissues with their cells intact and there is no immune reaction and the microscopic architecture is matched. For dental implant procedures, bone is often removed from another part of the jaw, i.e., the chin or back portions of the jaw, as an acceptable donor site. This limits the surgery to the mouth and avoids extraoral wounds and scarring.
Clinicians use several techniques to remove bone for grafting for intraoral procedures. In one technique, rotary instruments, such as rotary drills, are used to remove a piece or section of cortical bone from a local intraoral site in the maxilla or mandible. The cortical bone is often morsalized into a particulate form, either manually with a rongeur like instrument or in a bone mill. The particulate bone is then combined with blood to form an osseous coagulum, which is then positioned and packed into the osseous defect around the teeth or implant.
Other techniques for harvesting bone include using chisels to remove shavings from the surface of a bone and enable manual collection thereof. These instruments must be very sharp and the process is often awkward, repetitive and time consuming.
Other manual instruments such as bone files and rasps also remove bone. However, the efficiency of cutting and the ability to use the removed bone is greatly limited. Other known devices use a powered or manual saw which cuts off a part of the bone from a donor site and the cut-off bone then goes through a milling process to create bone fragments.